OkHttp 提供了对用户认证的支持。当 HTTP 响应的状态代码是 401 时，OkHttp 会从设置的 Authenticator 对象中获取到新的 Request 对象并再次尝试发出请求。Authenticator 接口中的 authenticate 方法用来提供进行认证的 Request 对象，authenticateProxy 方法用来提供对代理服务器进行认证的 Request 对象。
用户认证的示例：

OkHttpClient client = new OkHttpClient();client.setAuthenticator(new Authenticator() {public Request authenticate(Proxy proxy, Response response) throws IOException { String credential = Credentials.basic("user", "password"); return response.request().newBuilder() .header("Authorization", credential) .build();}public Request authenticateProxy(Proxy proxy, Response response) throws IOException { return null;}});

进阶
当需要实现一个 Basic challenge， 使用 Credentials.basic(username, password) 来编码请求头。

private final OkHttpClient client = new OkHttpClient();public void run() throws Exception { client.setAuthenticator(new Authenticator() { @Override public Request authenticate(Proxy proxy, Response response) { System.out.println("Authenticating for response: " + response); System.out.println("Challenges: " + response.challenges()); String credential = Credentials.basic("jesse", "password1"); return response.request().newBuilder() .header("Authorization", credential) .build(); } @Override public Request authenticateProxy(Proxy proxy, Response response) { return null; // Null indicates no attempt to authenticate. } }); Request request = new Request.Builder() .url("http://publicobject.com/secrets/hellosecret.txt") .build(); Response response = client.newCall(request).execute(); if (!response.isSuccessful()) throw new IOException("Unexpected code " + response); System.out.println(response.body().string());}